I wish to install a Siemens Logo PLC+additional modules to control my home heating system. This is a DIN rail device does this it have to be mounted in a BS7671-3 compliant enclosure? If the enclosure also include a 10A MCB for protecting the input supply cable and 3A MCB for protecting the relays, would this change the answer? Only one mains electrical circuit will be going into the box, it will be providing the power of a small electric underfloor heating system, circlation pump for wet underfloor heating, and power for valves to provide zone based heating control.
It would have been nice to use a enclosure with a window so the display of the logo could be seen without opening the enclosure, or perhaps being able to ventilate the box as it will have a 1.3A 24V power supply in it to power the automation. Both of which do not seem allowed with a fire proof BS7671-3 enclosure.
